The present invention relates to a buckle, more specifically, for example, to a buckle for maintaining a webbing in a fastened state by engaging with a tongue plate which is provided at the webbing of a vehicular seat belt device.
FIG. 15 shows an example of a conventional buckle (see Japanese Patent Application Publication (JP-B) No. 63-45203).
In this buckle 200, when a tongue plate 202 is inserted into an insertion portion 204 and an ejector (not shown) is moved, a button 206 is pushed by the ejector and is slid. Therefore, a protrusion 208 formed at the button 206 is separated from a latch 210, and the latch 210 can move in a direction of engaging with an engagement hole 212 of the tongue plate 202 (the direction of the arrow G). In an engaged state, the protrusion 208 of the button 206 abuts against the latch 210 so as to prevent the latch 210 from moving in a disengaging direction (the direction opposite to the arrow G). Accordingly, removal of the tongue plate 202 is prevented (i.e., a locked state), and an unillustrated webbing of a seat belt device is maintained in a state for fastening a fastener.
When the button 206 is pushed and slid in an unlocking direction (the direction of the arrow F), the protrusion 208 is separated from the latch 210 , and the latch 210 can move in the disengaging direction (the direction opposite to the arrow G).
In this type of buckle 200, in the locked state, the tongue plate 202 is in contact with the button 206 via the ejector without clearance. Accordingly, when the tongue plate 202 is pushed in the direction of the arrow F in the locked state, the button 206 is also moved in the unlocking direction via the ejector. Therefore, in order to prevent inadvertent unlocking even in such case, the protrusion 208 is formed in a sufficiently large size in consideration of a moving stroke of the button 206.
However, if the protrusion 208 is formed in a large size in this manner, the moving stroke of the button 206 at the time of unlocking is also increased in size. As a result, the entire buckle 200 is formed in a large size, and thus manufacturing cost is increased.
In consideration of such circumstances, it is an object of the present invention to obtain a buckle that can be manufactured at lower cost and is not unlocked even when a tongue plate is pushed in a locked state.
The invention is characterized by comprising: an engaging member, which can engage with a tongue plate inserted into an insertion portion up to a predetermined position; an operating member, which maintains the engaging member in an engaged state with respect to the tongue plate, and which moves the engaging member in a disengaging direction from the tongue plate by a predetermined operation; and an intermediate member, which forms at least one clearance between the intermediate member and a portion from the tongue plate to the operating member in the engaged state of the engaging member.
When the tongue plate is inserted into the insertion portion of the buckle up to the predetermined position, the engaging member engages with the tongue plate. Since the operating member maintains the engaging member in the engaged state, the tongue plate is locked and is thereby not removed inadvertently.
In the state in which the engaging member engages with the tongue plate, the intermediate member forms the clearance between the intermediate member and the portion from the tongue plate to the operating member. Accordingly, the operating member is free with respect to the tongue plate, and thus, even if the tongue plate is moved, the operating member is not moved as long as this clearance is not eliminated. Therefore, there is no need to form a member for preventing removal (e.g., protrusions or the like) in a large size to account for cases in which the operating member is moved and the tongue plate is thereby removed inadvertently when the tongue plate is pushed. As a result, the moving stroke of the operating member during disengagement of the engaging member can be reduced in size, and the entire buckle can be formed in a small size, and thus, the manufacturing cost of the buckle can be decreased.
The invention described in claim 2 is characterized in that, in the invention described in claim 1, the intermediate member is a swinging member, which is swingably attached to a supporting plate supporting the engaging member and the operating member or to the operating member, and which is pushed by the tongue plate so as to swing while the tongue plate is inserted into the insertion portion, and which forms the clearance in the engaged state of the engaging member with respect to the tongue plate.
Therefore, when the tongue plate is inserted into the insertion portion, the swinging member is pushed by the tongue plate so as to swing, and the clearance is formed between the swinging member and the portion from the tongue plate to the operating member in the state in which the engaging member engages with the tongue plate. In this way, due to a simple structure merely provided with the swinging member, the clearance can be formed between the swinging member and the portion from the tongue plate to the operating member, and thus, the manufacturing cost can be decreased.
The invention described in claim 3 is characterized in that, in the invention described in claim 2, the buckle includes an urging means which urges the engaging member to the engaged state, and the swinging member is formed integrally with the urging means.
Since the engaging member is urged to the engaged state by the urging means, the engaged state can be maintained more certainly.
Further, in the buckle provided with the urging means in advance, since the swinging member is formed integrally with the urging means, the number of parts is not increased, and the manufacturing cost is not increased.
The invention is also characterized in that the intermediate member is a moving member, which is provided at the operating member, and which moves the operating member by insertion of the tongue plate into the insertion portion and moves in a direction intersecting this moving direction orthogonally so as to form the clearance.
Therefore, when the tongue plate is inserted into the insertion portion, the moving member moves the operating member. Further, by the movement of the operating member, the moving member moves in the direction intersecting this movement orthogonally so as to form the clearance between the moving member and the portion from the tongue plate to the operating member. In this way, due to a simple structure merely provided with the moving member, the clearance can be formed between the moving member and the portion from the tongue plate to the operating member, and thus, the manufacturing cost can be decreased.
The invention is further characterized in that the swinging member is attached to the operating member, and includes a weighting body which moves inertially by an inertial force of a predetermined value or more in an unlocking direction applied to the operating member, and an engaging portion which engages with an engaged portion and prevents the swinging member from moving in the unlocking direction when the swinging member swings by an inertial movement of the weighting body.
In other words, for example, when a vehicle is in a state of rapid acceleration or rapid deceleration or the like, if inertial force of the predetermined value or more operates in the unlocking direction of the operating member (the direction for moving the engaging member in the disengaging direction from the tongue plate), the operating member tends to move in this direction. However, at that time, the weighting body moves inertially by receiving the inertial force and swings the swinging member. Due to this swing, the engaging portion engages with the engaged portion so as to prevent the swinging member from moving in the unlocking direction. Since the swinging member is attached to the operating member, the operating member is also prevented from moving in the unlocking direction. Accordingly, the engaging member is prevented from moving inadvertently from the tongue plate in the disengaging direction and is maintained in the locked state.
While the portion at which the engaged portion is provided is not limited particularly, the engaged portion can be formed at, for example, the cover or the like structuring the buckle. Accordingly, the number of parts can be prevented from increasing, and the manufacturing cost of the buckle can be decreased.
The invention is also characterized in that the buckle further comprises a moving member which moves on the basis of a movement of the tongue plate, and the intermediate member forms a predetermined clearance between the intermediate member and one of the moving member or the engaging member in the engaged state of the engaging member.